For example, there has been developed a high-level remote sensing technique for obtaining data to be utilized for land form decipherment, land-cover classification, and the like which are performed in cartography and scientific research.
Among data obtained by the remote sensing, an ortho-photo image is a planar color photographic image (RGB: raster) in which a surface layer photograph captured by an airplane (RGB: raster) is geometrically transformed into an orthographical projection map, and trees, buildings, roads, ground surfaces, grass fields and the like can be easily deciphered in a visual manner. Furthermore, the ortho-photo image is an actual on-site image, and thus the ortho-photo image has a strong visual appeal and is utilized recently for various systems. For example, patent literature 1 discloses that tree tops are obtained through the use of DEM (Digital Elevation Model) and DSM (Digital Surface Model) and these tops are displayed on trees of the ortho-photo image.
Meanwhile, there is a geological map in which geological features are expressed in different colors (RGB: raster) on a contour map.
Moreover, there is an altitude tints map. The altitude tints map expresses land form by means of performing tinting corresponding to an elevation (RGB: raster).
In addition, there is a face photograph. This face photograph is also an RGB image (raster) in a sense.
Furthermore, there is a red relief image map which is disclosed in patent literature 2. This red relief image map is a pseudo color image in which a steeper slope is expressed in redder color by making a gradient amount proportional to red saturation, and also a ridge and an independent peak are expressed in higher brightness and a valley and a depressed area are expressed in lower brightness, by making a ridge-valley degree proportional to lightness.